Ribbon cable connector



Nov. 28, 1967 E. OSHVA 3355599 RIBBON CABLE CONNECTOR I Original Filed June 5, 1961 INVENTOR. [UGANE OJ/iV/l United States Patent 3,355,699 RHBEQN CABLE CGNNECTOR Eugene Oshva, New York, N.Y., assignor to Burndy Corporation, a corporation of New York Original application June 5, 1961, Ser. No. 114,984, new

Patent No. 3,214,723, dated Oct. 26, 1965. Divided and this application Aug. 13, 1964, Ser. No. 389,394

7 Qlaims. (Cl. 339-99) This invention relates to electrical connectors, and more particularly to connectors for fiat flexible cables.

This application is a division of copending application Ser. No. 114,984, filed June 5, 1961 issued as Patent No. 3,214,723 on Oct. 26, 1965, and assigned to the same assignee as the present application.

Flat flexible ribbon cable is essentially a plurality of fiat or ribbon-like conductors disposed adjacent each other in a common plane and supported within a common dielectric covering. Such ribbon cables are manufactured in various ways; e.g., conductor strips may be disposed between two dielectric sheets and the sheets then bonded together; or metal foil sheets may be cemented to a dielectric sheet, the foil milled into strips and a second dielectric sheet cemented over the milled strips. Many flat flexible cables are formed of copper ribbons sandwiched between two layers of dielectric such as various forms of polyesters, polyethylene, fluorinated plastics, polyvinyls or silicone rubber.

A major problem in the use of flat ribbon cables is their connection to electrical equipment or to each other. The cable conductors are thin, closely spaced, and insulated on all sides; they may have a surface lacquer or oxide coat even though they are covered by the dielectric layers, or oxide coatings may form when the dielectric is removed to prepare a connection.

Various methods of attaching connectors to such cables have been proposed. In one method, the insulation is stripped from the conductors and the multicontact connectors are soldered or clamped to them. Unfortunately, stripping weakens the end of the cable, exposes the included conductors to possible damage; stripping may actually nick or cut the conductors due to their thinness. Soldering has been found to be inconvenient to accomplish and difiicult to control, especially with the fragile conductors involved in these cables, while clamping is subject to problems of relaxation and creep.

It is, therefore, an object of this invention to provide a connector having a plurality of contact elements, each of which will make a secure mechanical and electrical connection with a conductor in a Hat flexible cable.

It is another object to provide such a connector which may be readily connected to and disconnected from fiat cables.

It is yet another object to provide a connector for such cables which requires no preliminary treatment such as stripping of the cable insulation.

A feature of this invention is a connector having a plurality of spaced-apart, toothed contacts, each contact having a plurality of teeth which are in effect uniformly varying in length and which are adapted to penetrate into the cable to varying depths to scrape an included conductor while making mechanical and electrical contact therewith.

These and other objects and features of this invention will become more apparent through reference to the following description taken in conjunction with the accompanying drawings, in which:

3,355,699 Patented Nov. 28, 1967 FIG. 1 is a perspective view of a cable-to-cable connec' tion utilizing two identical terminal connectors in accordance with this invention;

FIG. 2 is an exploded perspective view of the connector of FIG. 1;

FIG. 3 is a detail of FIG. 2 taken along line 3-3;

FIG. 4 is a detail of FIG. 2 taken along line 4-4;

FIG. 5 is a detail of FIG. 2 taken along line 5-5;

FIG. 6 is a detail of FIG. 5 taken along line 6-6;

FIG. 7 is a variant of the contact-pressure bar arrangement of FIG. 2;

FIG. 8 is a detail of a typical contact tooth showing the scraping action of the tooth relative to the cable insulation.

Referring now more particularly to the drawings, FIGS. 1 and 2 illustrate one embodiment of this invention which provides controlled scraping penetration and contacting of a fiat cable. In the illustrated embodiment two identical cable-terminating connector assemblies 211 and 213, are used to connect two flat cables to each other within an interposed adaptor block 215.

A contact block 217 carries a plurality of spaced-apart contacts 219 shown in detail in FIG. 4. One end of the block 217 and of each contact 219 is formed with a V- shaped recess or jaw 221. Each contact has a plurality of teeth 223 formed into the inner surface of its jaw 221. A V or wedge-shaped pressure bar 225 shown in detail in FIG. 3 is provided to mate with the recess 221 in the block 217 and in the contacts 219. A cable guide 227 and jack screws 229 may be provided to clamp the bar 225 to the block 215; in addition, a cable strain-relief 231 which has fingers 233 having holes 235 which engage tabs 237 on the adaptor block 215 may also be provided to assure that the cable retains its position relative to the block.

In use, a flat flexible cable 35, shown in FIG. 1 and in phantom view in FIG. 2, is passed through a slit 239 in the cable strain relief 231, and under, around and over the pressure bar 225 so as to pass back through the relief slit 239.

Thus, when the fiat cable 35 has passed around the pressure bar 225, and the bar is tightened against the contact block 217, the teeth 223 of each contact 219 will penetrate angularly into the cable surface to different depths to insure at least some teeth of each contact scraping into good connection with the related ribbon conductor 37.

The teeth 223 of each contact may be made of uniformly varying length, being shortest at the tip of the left-hand portion 221L of the jaw 221, of medium length at the center or apex of the V-shaped jaw, and longest at the tip of the right-hand portion 221R of the jaw. Although each contact is here shown to have teeth projecting from the left and right portions of the jaw, it is also possible that two separate contacts may have teeth projecting independently from the left and the right portions respectively. The use of teeth of varying length ensures that each tooth will penetrate the cable to a slightly diiferent depth. Several teeth will thus always penetrate the cable insulation through to the conductor. Since the depth of tooth penetration becomes progressively deeper toward the free end of the cable (if it is properly positioned around the pressure bar 225), even if a contact tooth does unintentionally pierce the conductor, even severing it, the connection will not be affected since the remaining teeth have made a proper connection nearer the vital end of the cable which extends to the other circuits or apparatus. If desired, the contacts may be made narrower in w lldth than the conductor in a given cable to ensure that iercing by a tooth will not completely sever a conductor.

With the teeth 223 thus driven into the cable 35 at a light angle, rather than perpendicularly, a slight relative ongitudinal motion between the cable and the teeth is .chieved, whereby the teeth will tend to scrape away he insulation and surface coating on the cable conductors s shown in FIG. 8.

The adapter block 215 which is interposed between the W assemblies 211 and 213, may be seen to have a pluality of passages 241 therethrough into which the hernaphodite tabs 243 of each contact 219 may be inserted. Within the passages 241, the tabs 243 of one assembly nate with the corresponding tabs on the mating connector issembly to interconnect the two cables 35. These terninal tabs may preferably be spring-tempered and lightly bowed to facilitate proper wiping action upon nating engagement, It is apparent that terminal or inter :onnecting arrangements other than the tabs 243 may be )rovided in conjunction with the contacts 219 to permit :onnection of the contacted cable to other cables or apiaratus without departing from the scope of this inendon.

The invention has thus been described but it is desired .0 be understood that it is not confined to the particular :orms or usages shown and described, the same being nerely illustrative, and that the invention may be caried out in other ways without departing from the spirit 3f the invention; therefore, the right is broadly claimed :0 employ all equivalent instrumentalities coming within he scope of the appendant claims, and by means of which objects of this invention are attained and new re- ;ults accomplished, as it is obvious that the particular embodiments herein shown and described are only some of the many that can be employed to obtain these objects and accomplish these results.

I claim:

1. A strip cable connector comprising a strip cable composed of a plurality of parallel, spaced electrical conductor ribbons enclosed within a rupturable material; a wedge of material located between the ends of said strip :able and about which said strip cable is wrapped to render said strip cable more rigid and properly positioned; an insulator body having a compartment therein; a plurality of electrical contact means disposed within said compartment in corresponding relationship to said conductor ribbon, each of said contact means having terminal means thereon; said contact means each having a slot therein the entrance of which has corners thereon that locally rupture and strip the material of said strip cable to expose the conductor ribbons to an intimate electrical contact with said contact means when the stabalized strip cable is inserted into said slots.

2. A strip cable connector member comprising a strip cable having a plurality of spaced, flat, parallel conductor ribbons lying in a common plane and enclosed within a rupturable insulation material, a support member having a generally straight edge over which said strip cable is bent with said edge extending transversely relative to said conductor ribbons, and a connector member body having a plurality of spaced, parallel contact members supported therein, said contact members each having a corner thereon, said support member and strip cable being slidable in said body so that individual conductor ribbons of the strip cable slide longitudinally in alignment with respective contact members, said corners on the contact members engaging the strip cable proximate said edge of the support member and locally rupturing and stripping the insulation material of the strip cable to expose the conductor ribbons to intimate electrical contact with respective contact members.

3. A strip cable connector comprising a strip cable composed of a plurality of parallel, spaced conductor rib bons enclosed between sheets of rupturable material that are bonded together; a wedge of material about which the strip cable is folded to render the strip cable more rigid and properly positioned; an insulator body having a compartment therein defined by a front wall, a pair of side walls, and a pair of end walls; a plurality of electrical contact means disposed within said compartment, in corresponding spaced relationship to certain of said conductor ribbons, said contact means having terminal means thereon that are exposed through respective openings in at least one of said walls; said contact means each having a slot therein the entrance of which has corners thereon that locally rupture and strip one sheet of said material of said strip cable to expose the conductor ribbons to an intimate electrical contact with said contact means when the stabilized strip cable is inserted into said slots.

4. A strip cable connector comprising a strip cable composed of a plurality of parallel, spaced conductor ribbons enclosed between sheets of rupturable material that are bonded together; a wedge of material about which the strip cable is folded to render the strip cable more rigid and proprly positioned; an insulator body having a compartment therein defined by a front wall having openings therein, a pair of side walls and a pair of end walls; a plurality of electrical contact means disposed within said compartment, in corresponding spaced relationship to said conductor ribbons, said contact means having terminal means thereon that are exposed through the respective openings in said front wall; said Contact means each having a slot therein the entrance of which has corners thereon that locally rupture and strip one sheet of said material of said strip cable to expose the conductor ribbons to an intimate electrical contact with said contact means when the stabilized strip cable is inserted into said slots.

5. A strip cable connector member comprising a strip cable having a plurality of spaced, fiat, parallel conductor ribbons lying in a common piane and enclosed within rupturable insulation material, a support member having a generally flat surface terminating at a generally straight edge, the strip cable extending over said surface and being bent over said edge with said edge extending transversely relative to said conductor ribbons, and a connector member body having a plurality of spaced, parallel contact members supported therein, said contact members each having a corner thereon, said support member and strip cable being slidable in said body so that individual conductor ribbons of the strip cable slide longitudinally in alignment with respective contact members, said corners on the contact members engaging the strip cable proximate said edge of the support member and locally rupturing and stripping the insulation material of the strip cable to expose the conductor ribbons {)0 intimate electrical contact with respective contact memers.

6. A strip cable connector member comprising a strip cable having a plurality of spaced, fiat, parallel conductor ribbons lying in a common plane and enclosed within rupturable insulation material, a support wafer having a generally straight edge over which said strip cable is folded with said edge extending transversely relative .to said conductor ribbons, and a connector member body having a plurality of spaced, parallel contact members supported therein, said contact members each having a slot therein the entrance of which has corners thereon, said support wafer and strip cable being slidable in said body so that individual conductor ribbons of the strip cable slide longitudinally in alignment with respective contact members, said corners on each of the contact members engaging the strip cable proximate said edge of the support wafer and locally rupturing and stripping the insulation material of the strip cable to expose a respective conductor ribbon to intimate electrical contact with the contact member.

7. A connector comprising: a flat conductor cable having a plurality of flat conductor ribbons spaced transversely and encased in an insulating sheath; first and second connector parts, one of said connector parts having means for securing thereto a longitudinally extended portion of said cable, the other of said connector parts having a number of contact elements each having at least a point, means supporting said elements in said other connector part in transversely spaced relation corresponding to the transverse spacing of at least certain of said conductor ribbons, means for interconnecting said connector parts together with said longitudinally extended portion of said cable and said contact element point disposed at an angle relative to one another so that said points penetrate said sheath and engage said certain conductor ribbons, said elements being in contact with said certain ribbons along an elongated section of one side of the respective elements.

References Cited UNITED STATES PATENTS 3/1949 Tuttle 339-99 X 2,888,658 5/1956 Welch 339-474 X 2,951,112 8/1960 Dahlgren 339-103 X 2,981,918 4/1961 Gluck et a1. 339-103 3,084,302 4/ 1963 Braeutigam 339-176 3,201,744 8/1965 Dean 339-97 FOREIGN PATENTS 753,736 8/1933 France. 240,937 10/ 1925 Great Britain. 700,490 12/ 1953 Great Britain.

MARVIN A. CHAMPION, Primary Examiner. ALFRED S. TRASK, JOSEPH D. SEERS, Examiners. J. H. MCGLYNN, Assistant Examiner. 

1. A STRIP CABLE CONNECTOR COMPRISING A STRIP CABLE COMPOSED OF A PLURALITY OF PARALLEL, SPACED ELECTRICAL CONDUCTOR RIBBONS ENCLOSED WITHIN A RUPTURABLE MATERIAL; A WEDGE OF MATERIAL LOCATED BETWEEN THE ENDS OF SAID STRIP CABLE AND ABOUT WHICH SAID STRIP CABLE IS WRAPPED TO RENDER SAID STRIP CABLE MORE RIGID AND PROPERLY POSITIONED; AN INSULATOR BODY HAVING A COMPARTMENT THEREIN; A PLURALITY OF ELECTRICAL CONTACT MEANS DISPOSED WITHIN SAID COMPARTMENT IN CORRESPONDING RELATIONSHIP TO SAID CONDUCTOR RIBBON, EACH OF SAID CONTACT MEANS HAVING TERMINAL MEANS THEREON; SAID CONTACT MEANS EACH HAVING A SLOT THEREIN THE ENTRANCE OF WHICH HAS CORNERS THEREON THAT LOCALLY RUPTURE AND STRIP THE MATERIAL OF SAID STRIP CABLE TO EXPOSE THE CONDUCTOR RIBBONS TO AN INTIMATE ELECTRICAL CONTACT WITH SAID CONTACT MEANS WHEN THE STABILIZED STRIP CABLE IS INSERTED INTO SAID SLOTS. 